In article , Len Krauss
wrote:


Second step is to, while polishing, agitate fuel at bottom of tank using a
small L-shaped air discharge pushed down to tank bottom on a rod or dowel
and turned about as much as possible. Obviously the fuel furthest away from
the discharge will get the least agitation and baffles will reduce degree of
agitation for sure. But with the L-shaped discharge at the bottom and
turned, disturbance will flow through baffle bottom notches. The basic idea
is to get crud in suspension and moving so it can be captured by the
polishing pick up and filtered out.


You are correct!!!! but dont use air.

Tank farms use whats known as a *sparging nozzle* to keep the tank in
constant agitation. Its simply a jet of liquid that discharges into a
throat of a venturi section. The velocity from the jet into the
venturi 'entrains' the liquid in the bottom of tank to circulate. A
sparger moves the layers on the bottom of the tank towards the top;
hence, affects a mixing.
(for techies amoung us, a sparging nozzle {sparger} in an 'open inlet
eductor')

If you use air, you generate a lot of air entrainment which can settle
out and coalesce into larger and larger bubbles of air .... and block
the downstream system.